Republican Senator John Thune says the U.S. is at a crossroads in the war in Afghanistan.

Thune says he signed a letter with Senator John McCain and other GOP members of the Senate Armed Services Committee asking the chairman to call a hearing with the top commanders in Afghanistan so the committee can better understand what's at stake.

Thune said Wednesday that President Barack Obama's position seems to have shifted. First, Thune says Obama called for disrupting and defeating al-Qaida. But after U.S. commanders quantified what's needed to do that - including more troops - Thune says Obama seemed to hedge and move away from his earlier position.

Thune says the president will have support if he agrees with his commanders.